Good evening , My mom 90 years old starting to take Mirtazapine for anxiety 7m at night. Ever since she started this medicine she has her fingers constantly in her mouth, now she is taking her dentures out of her mouth every other ten minutes. I she makes a snapping sound constantly with her mouth. I took her to the dentist, they did not see a mayor problem with her gums.She is also lethargic most of the day.